单选题设A，B是两个事件，且，P(B)＞0，则下列选项必然成立的是()．

单选题Inthemultiplicationproblemabove,F,G,andHrepresentuniqueodddigits.Whatisthevalueofthethree-digitnumberFGF?

单选题To write a summary effectively, you will need to ______ words for phrases, and phrases for sentences. A. convert B. complement C. substitute D. design

单选题设，则x=1为f(x)在[-2，2]上的______

单选题曲线______A.有一个拐点B.有两个拐点C.有三个拐点D.无拐点

单选题用10以内的质数组成一个三位数，使它能同时被3、5整除，这个数最小是m，最大是n，则n-m等于______。 A．360 B．345 C．330 D．375

单选题设函数f(x)与g(x)均在(a，b)可导，且满足f'(x)＜g'(x)，则f(x)与g(x)的关系是( ) A．必有f(x)＞g(x) B．必有f(x)＜g(x) C．必有f(x)=g(x) D．不能确定大小

单选题桌上放着红桃、黑桃和梅花三种牌，共20张。 Ⅰ．桌上至少有一种花色的牌少于6张。 Ⅱ．桌上至少有一种花色的牌多于6张。 Ⅲ．桌上任意两种牌的总数将不超过19张。 从以上陈述中能得出以下哪项结论? A．Ⅰ、Ⅱ。 B．Ⅰ、Ⅲ。 C．Ⅱ、Ⅲ。 D．Ⅰ、Ⅱ和Ⅲ。 E．Ⅰ、Ⅱ和Ⅲ都不能得出。

单选题下列无穷级数中收敛的是______A．B．C．D．

单选题If the technological revolution continues to have its effects, there will be fewer and fewer jobs available, particularly to school-leavers and those over the age of fifty. (1) there are only half the number of jobs in the future, men and women will have to share them. Two people will (2) work only twenty hours each (3) the forty they are currently (4) to. It is a well-known fact that those who suffer from stress at work are often not high-powered executives but (5) workers doing boring, (6) jobs, especially those on production lines. Unemployment often has a (7) effect on its victims. If we wish to prevent this type of stress and the depression that frequently follows long periods of it, we will have to find ways of educating people to (8) this sudden increase in leisure time. Many have already (9) pills and tablets to (10) sleeplessness and anxiety, two of the symptoms of long-term stress and depression. In America, we (11) $ 650 million a year on different kinds of medicines. We (12) an astonishing three million sleeping tablets every night. (14) these "drugs of the mind" can be extremely useful in cases of crisis, the majority of patients would be (14) without them. The boredom and frustration of unemployment are not the only (15) of stress: poor housing, family problems, overcrowding and financial worry are all significant factors. (16) , doctors believe that if people learnt to breathe properly, took more exercise, used their leisure time more (17) and expressed their anger instead of (18) it up, they would not depend so much on drugs, (19) treat only the (20) and not the cause of the stress.

单选题设α1=(1，0，2，c1)T，α2=(0，2，1，c2)T，α3=(1，2，3，c3)T，α4=(1，0，1，0)T其中ci(i=1，2，3)为任意实数，则

单选题如果数列{an}的前n项的和，那么这个数列的通项公式是()．

单选题设随机变量X服从标准正态分布N(0，1)，则E[(X-2) 2 e 2X ]= A．1． B．2． C．e 2 ．D．2e 2 ．

单选题设α为常数，则级数